Research is being directed toward the determination of factors limiting diagnostic performance from dental radiographs. Of specific interest, is the consideration of task-specific questions from the point of view of information theory. Specific experiments involve selective manipulation of factors known to reduce the information capacity of radiographic displays and the determination of the factors (if any) on diagnostic performance by human interpreters. This approach permits specification of diagnostically meaningful information in terms of spatial frequency spectra found to be essential for specific diagnostic tasks. Related efforts also include modeling the effects of pertinent variables in a complete radiographic system in order to specify the influence of variations in spectral sensitivity of the detector, alterations in beam geometry, changes in the energy distribution of the primary beam, etc. Promising models have been tested clinically and found to yield results consistent with actual measured values. Predictions based on these models suggest practical bases for optimizing specific radiographic tasks.